Αιγισθος
The son of the incestuous relationship between Thyestes and his daughter Pelopia (Table 2). Thyestes was banished by his brother Atreus and lived at Sicyon, a long way from Mycenae. He spent his time thinking of ways in which he could avenge himself on his brother, who had killed his sons, and an oracle told him that he would find an avenger in the form of a son by his own daughter. Accordingly he waited for Pelopia while she was performing a sacrifice by night at Sicyon and secretly raped her when she returned. Then he disappeared, but during the rape Pelopia stole his sword. Later, Atreus married Pelopia without knowing who she was. Pelopia abandoned the incestuously conceived infant after his birth but Atreus discovered the child among shepherds who had taken him in and fed him with goat's milk (the source of his name since αις means 'goat'). Atreus took the child back with him and brought him up as his son.
When he became a young man Atreus told him to go to Delphi, capture Thyestes and bring him back, since he intended to put Thyestes to death. (Another version of this story, written by a tragic poet, says that Agamemnon and Menelaus, Atreus' two sons by Aerope, were charged with this mission.) Aegisthus obeyed, brought back Thyestes and was ordered to kill him. Aegisthus was wearing a sword which his mother had given him, the same sword which had been stolen on the night of the rape. When Thyestes saw the sword, he asked Aegisthus who had given it to him. The young man replied that it was a gift from his mother. Thyestes then begged for Pelopia to be summoned, and he then disclosed the secret of Aegisthus' birth. Pelopia seized the sword and stabbed herself in the breast; Aegisthus pulled it out and went to find Atreus, who was conducting a sacrifice on the shore, believing that his brother was already dead, and delighted at having caused the death. Aegisthus killed him and thereafter he and Thyestes ruled Mycenae.
When Agamemnon and Menelaus were at Troy, Aegisthus, who had stayed behind in the Peloponnese, tried to seduce Clytemnestra. For a long time he had no success, as she had an old seer named Demodocus with her, left behing by Agamemnon, but eventually Aegisthus disposed of Demodocus, and Clytemnestra offered no more resistance. Aegisthus lived with her until Agamemnon returned. Aegisthus posted watchers on the shore to give early notice of Agamemnon's homecoming and when the latter did return, he was received with great demonstrations of friendship and happiness. A great feast was prepared for him, during which he was killed by Clytemnestra. Aegisthus subsequently reigned for seven more years over Mycenae before he was killed by Orestes, Agamemnon's son. Aegisthus had two children, Aletes and Erigone.
{E2 DICTIONARY OF CLASSICAL MYTHOLOGY}
Table of Sources:
- Hyg. Fab. 87; 88; 117; 252
- Sophocles, Aegisthus(?); Aletes; Thyestes (lost tragedies, Jebb-Pearson I, pp. 21; 62ff.; 185ff.)
- Aeschylus, Ag. 1583ff.
- Hom. Od. 3, 263ff.; 4, 517ff.
- See also Orestes; Atreus